A process for the preparation of a mixture of dichlorophenylphosphane C.sub.6 H.sub.5 PCl.sub.2 and chlorodiphenylphosphane (C.sub.6 H.sub.5).sub.2 PCl in which triphenylphosphane (C.sub.6 H.sub.5).sub.3 P and phosphorus trichloride PCl.sub.3 are reacted at temperatures of 320.degree. to 700.degree. C. in an autoclave or in a quartz tube in an electric furnace is known from U.S. Pat. No. 4,521,347.
The disadvantage of the known process is that the reaction product contains white phosphorus, which makes working up of the reaction product by distillation very difficult.